1. Year 7: Length and Area Perimeter The perimeter of a shape is the total distance around the edge of a shape. Perimeter is measured in cm A regular shape has all sides the same length and all angles the same size. Example 1 1) Calculate the perimeter of a hexagon with side length 5cm. P= 6 × 5 = 30cm 5cm

2. In harder perimeter problems, fill in all missing sides before starting to calculate the perimeter. P= 20 + 5 × 5 + 2 × 10 + 7.5 + 7.5 = 80cm 7.5cm 5cm 7.5cm Example 2 Calculate the perimeter of the following. 20cm 10cm Year 7: Length and Area Perimeter

3. Special case The perimeter of an “L” or “T” shape is the same as its related rectangle. Examples Calculate the perimeter of the following. 2)3) 13cm 24cm 11cm 6cm 4m15m 6m 8m 9m 7m P= 2 × (24 + 13) = 74cm 14m P= 2 × (14 + 15) = 58m Year 7: Length and Area Perimeter